docs: def alias(self, v, stat='dummy'):
          """Return a representation of a value suitable for use in historical queries.
  
          It will behave much as if you assigned the value to some entity and then used its
          ``historical`` method to get a reference to the set of its past values, which
          happens to contain only the value you've provided here, ``v``.
  
          :arg v: the value to represent
          :arg stat: what name to pretend its stat has; usually irrelevant
  
          """
          from .util import EntityStatAccessor
          r = DummyEntity(self)
          r[stat] = v
          return EntityStatAccessor(r, stat, engine=self)